This patent application is related to U.S. patent application Ser. No. 09/747,536, entitled Electrically and Environmentally Sealed Mechanical Control Device for an Electronic Device by David Wallis et al., and filed on even date with this patent application.
This invention relates generally to broadband communication systems, such as cable television systems, and taps used in such systems, and more specifically to the provision of AC power to subscriber premises in a broadband communication system.
A communication system 100, such as a two-way cable television system, is depicted in FIG. 1. The communication system 100 includes headend equipment 105 for generating forward signals that are transmitted in the forward, or downstream, direction along a communication medium, such as a fiber optic cable 110, to an optical node 115 that converts optical signals to radio frequency (RF) signals. The RF signals are further transmitted along another communication medium, such as coaxial cable 120, and are amplified, as necessary, by one or more distribution amplifiers 125 positioned along the communication medium. Taps 130 included in the cable television system split off portions of the forward signals for provision to subscriber equipment 135, such as set top terminals, computers, and televisions. In a two-way system, the subscriber equipment 135 can also generate reverse signals that are transmitted upstream, amplified by any distribution amplifiers 125, converted to optical signals, and provided to the headend equipment 105.
A cable television tap 130 that splits the forward signal is depicted in FIG. 2. The tap 130 includes an input port 205 for receiving the signal, an output port 210 for passing the signal through to other portions of the communication system 100, and subscriber ports 215, each of which couples a portion of the signal to subscriber equipment. A tap 130 commonly includes four, eight, or sixteen subscriber ports 215, although an even larger number of subscriber ports 215 can be included if necessary.
AC (alternating current) power can also be provided through the cable television system 100 for powering telephones and other subscriber equipment. In this case, the AC power typically travels through the same distribution system, including the taps 130, so that it can be provided to the subscriber equipment on the same communication medium that provides the information signal. In operation, the tap 130, which includes a power distribution unit (PDU) 220, receives the forward signal, including the AC power, and provides, via AC port device connectors 225, a plurality of AC power outputs and, via the subscriber ports 215, a plurality of information signal outputs.
While the conventional multimedia tap 130, which includes the PDU 220, meets the objective of providing information signals while also supplying AC power to the subscriber, there are some disadvantages presented by the conventional tap 130. To activate a conventional PDU 220, the cover 230 needs to be removed via a number of screws or fasteners. Each connector 225 has an associated internal power jumper (not shown). The power jumpers are positioned in either the pass position, which activates an AC port device connector 225, or in a block position, which disables any power flow through a particular connector 225. There are several disadvantages with this method of supplying power to the subscribers. One disadvantage is the necessity of removing the PDU cover 230 to access the internal jumpers. A second disadvantage is the possibility of dropping a jumper as a result of having to physically remove and reposition the jumper to either the pass or block position. Typically, a large proportion of the installed taps 130 are hanging on aerial cable within the cable system 100. To access a tap 130 that is aerially installed is costly; in addition, if a jumper is dropped to the ground while repositioning, the operator consumes much time in either locating the jumper on the ground or preparing another jumper for its replacement.
In light of the disadvantages to the cable operator, what is needed is a less cumbersome multimedia tap 130 that offers flexibility in the distribution of AC power.
A product is needed that incorporates the required specifications for passing AC power to the subscriber, but also enhances the product with user-friendly features.